monogram pricing

What is the average price for a 3 letter monogram? I have just bought a PR620 machine and really don't know what to charge for simple monograms. I am doing some large original shirt designs (on my shirts) and am charging shirt prices based on the number of stitches and the cost of the shirt.

I have had requests for monograms and have charged $3 for one large initial and $5 for three. High or low?

Also, what is the average charge for small 3 letter monograms on a men's shirt cuff?

If someone can tell me if I am inthe ball park, I would be so appreciative!

I believe you are in the ball park - $3.00 is what I charge at fairs and craft shows for one large initial . but I found some pricing info online based on the number of stitches that may be helpful - i posted it below - also I have put names on things and charge $6.00 up to seven letters and $1.00 for each additional letter. I have never gotten negative feedback about the $6.00